THE GRANITIC ROCKS OF THE PIKES PEAK 
QUADRANGLE: 
GENERAL RELATIONS 
Frew natural features in the west are better known by name 
and form than Pikes Peak, which has served so often as a goal 
for the pioneer and traveler or as a fitting subject for the pho- 
tographer and artist. Its prominence arises from its position as 
the landmark first seen by the traveler moving westward, and 
from the abruptness with which it rises 8000 feet above the 
_ plateau at Colorado Springs. 
Moreover, the rapid developments in mining at Cripple Creek 
and the papers’ that have recently appeared on the subject have 
increased the interest in the area and have directed thought to 
its geology. 
In the present paper it is proposed to give a summary of the 
results obtained from a field and detailed laboratory study of the 
t Published by permission of the Director of the U. S. Geological Survey. 
The field work for the present paper was carried on by the writer while a field 
assistant in the party of Mr. Whitman Cross who directed the work and suggested the 
probiems to be studied. Many of the specimens were collected by Mr. Cross, and his 
field notes have been used freely. For the constant willingness to give assistance 
and the freedom in the use of notes, the writer wishes to express his gratitude to Mr. 
Cross, who furnished the opportunity to study so extensive an area. 
2 WHITMAN Cross: Intrusive Sandstone Dikes in Granite, Bull. Geol. Soc. of 
Am., Vol. V., 1894, pp. 225-230; Geology of the Cripple Creek Gold Mining Dis- 
trict; Proc. Colo. Sci. Soc., June 4, 1894. 
R. A. F. PENROSE, JR.: The Ore Deposits of Cripple Creek, Colo. Jdzd. 
E. B. MATHEWS: The Granites of the Pikes Peak Area, Bull. Geol. Soc of Am., 
Vol. VI, 1894, pp. 471-473. 
WHITMAN Cross and R. A. F. PENROSE, JR.: Geology and Mining Industries of 
the Cripple Creek District, Colo. Part I, General Geology, WHITMAN Cross; Part 
II, Mining Geology, R. A. F. PENROSE, JR. Sixteenth Ann. Rept. Dir. U.S. Geol. 
Sury., Il, Washington, 1895, pp. 13-217. 
W. O. Crosspy: The Great Fault and accompanying Sandstone Dikes of Ute 
Pass, Colorado, Science, new series, Vol. V, 1897, pp. 604-607. Archean Cambrian 
Contact near Manitou, Colorado, Bull. Geol. Soc. of Am., Vol. X, 1899, pp. 141-164. 
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